WO2007015307A1

WO2007015307A1 - Plasma display device

Info

Publication number: WO2007015307A1
Application number: PCT/JP2005/014347
Authority: WO
Inventors: Makoto Onozawa; Hideaki Ohki
Original assignee: Fujitsu Hitachi Plasma Display Limited
Priority date: 2005-08-04
Filing date: 2005-08-04
Publication date: 2007-02-08
Also published as: JPWO2007015307A1; US20090079722A1

Abstract

Provided is a plasma display device, in which a brightness difference caused in a plasma display panel of a large screen is reduced. In order to reduce the value of a streaking or a brightness difference on the plasma display panel screen and to reduce the brightness difference between the central portion and the two end portions of the screen, the plasma display device comprises current limiting means (8x) is interposed for each X-electrode between the X-electrode and an X-electrode drive circuit (3), and current limiting means (8y) is interposed for each Y-electrode between the Y-electrode and a Y-electrode drive circuit (4).

Description

Specification

Plasma display device

Technical field

[0001] The present invention relates to a plasma display device. More specifically, the preferred embodiment of the present invention provides a plasma display apparatus that reduces the difference in luminance that occurs in a large-screen plasma display panel.

Background art

As shown in FIG. 4, a conventional plasma display device processes an input video signal by a signal processing circuit 1 and supplies it to a drive control circuit 2. In this drive control circuit 2, control signals to be supplied to the X electrode drive circuit 3, the Y electrode drive circuit 4, the address electrode drive circuit 5, and the scan circuit 6 are formed based on the output signal of the signal processing circuit 1. . Each drive circuit and scan circuit 6 supplies a drive pulse to the plasma display panel 7 based on the control signal.

In a plasma display device having a large screen of a large plasma display panel 7, it is important to make the brightness of the entire screen uniform and to prevent uneven brightness on the screen.

[0003] Patent Document 1 describes a method of reducing a luminance difference by dividing an X electrode and a Y electrode into a plurality of blocks and intersecting boundaries between the blocks.

In FIG. 1 of Patent Document 1, the plurality of sustain electrodes of the PDP are divided into a plurality of blocks. A sustain electrode of a part of each block is disposed between the sustain electrodes of other blocks at the boundary of each of the plurality of blocks. The plurality of sustain drivers are connected to the sustain electrodes of the corresponding block.

Patent Document 1: Japanese Unexamined Patent Publication No. 2000-284747

Disclosure of the invention

Problems to be solved by the invention

In the plasma display device shown in FIG. 4, when the pattern shown in FIG. 5 is displayed, the brightness of the white display region sandwiched between the black display and the black display on the screen, the S1 brightness, There may be a difference between the brightness of the white display area with white edges and the S2 brightness.

This luminance difference is called streaking. Streaking is defined by the following equation. Streaking = (S 1 brightness—S2 brightness) ZS 1 brightness X 100 (%)

The conventional plasma display device has a problem that the streaking value is large, and reducing the streaking value is an important issue for improving the image quality. The streaking value is large, and in the conventional plasma display device, a voltage drop occurs in the sustain voltage waveform shown in FIG. 6, and the peak value in the sustain current waveform increases. When this voltage drop was large, the streaking value was also found to be large.

In addition, the conventional plasma display device has a problem in that a difference in luminance occurs between both end portions and the central portion of the plasma display panel screen. The reason for this difference in brightness will be explained with reference to Figs.

FIG. 7 is a diagram modeling the five cells in which the plasma display panel 7 is arranged in the horizontal direction. In Fig. 7, assuming that the discharge currents flowing between the X and Y electrodes are equal and V in each light emitting cell,

11 = 5 * 1

12 = 4 * 1

13 = 3 * 1

14 = 2 * 1

15 = 1

16 = 1

17 = 2 * 1

18 = 3 * 1

19 = 4 * 1

110 = 5 * 1

It can be expressed as.

Assuming that the resistance Rp between cells is equal, the Y electrode voltage Vsy and the X electrode voltage Vsx in cells A to E are VAy = -Vs

VBy = VAy- Rp water 12: = Vs-4RpI

VCy = VBy- Rp water 13: = Vs- 7RpI

VDy = = VCy--Rp water 14 = Vs- 9RpI

VEy = VDy- Rp water 15: = Vs-10 RpI

VEx = 0

VDx = -VEx ^ Rp water 19 = 4RpI

VCx = VDx ^-Rp water 18 = 7RpI

VBx =: VCx DOO-Rp water 17: = 9RpI

VAx = = VAx— _Rp water 16 = 10RpI

It can be expressed as:

From the above, the difference (Vsy-Vsx) between the voltage Vsy of the Y electrode Vsy and the voltage Vsx of the X electrode in cells A to E is Vd = lORpI.

VAy-VAx = Vs-10RpI = Vs-Vd

VBy VBx = Vs- l 3RpI

VCy-VCx = Vs-14RpI

VDy VDx = Vs- 13RpI

VEy-VEx = Vs-10RpI = Vs-Vd

It can be expressed as.

[0006] FIG. 8 shows this relationship in a graph. From Fig. 8, it can be seen that the voltage during discharge between the X and Y electrodes (Vsy – Vsx) between the cells increases at both ends of the screen, which is smaller at the center of the screen. When the number of cells is large, the brightness at the center of the screen is low, the discharge voltage is low, the discharge voltage is high, and the brightness at both ends is high.

As a conventional example for reducing the luminance difference on the screen, there is a method described in Patent Document 1 above. The above-mentioned conventional example is intended to reduce the luminance difference between lines. It was not considered until the problem of both the luminance difference between the central part and the both ends of the screen was solved.

An object of the present invention is to reduce the streaking value and at the same time, The purpose is to reduce the luminance difference between both ends.

Means for solving the problem

In order to achieve the above object, the plasma display device of the present invention is provided with current limiting means 8x and 8y individually for each X electrode between each X electrode and the X electrode driving circuit 3, The main feature is that current limiting means 8x and 8y are individually provided for each Y electrode between the Y electrode and the Y electrode drive circuit 4.

The invention's effect

[0009] According to the present invention, it is possible to reduce the streaking value and at the same time reduce the luminance difference between the central portion and both end portions of the screen.

Brief Description of Drawings

[0010] FIG. 1 is a diagram of an embodiment of a plasma display device of the present invention.

FIG. 2 is a diagram showing the effect of reducing the streaking of the plasma display device of the present invention.

FIG. 3 is a diagram showing the effect of improving the voltage drop due to the internal resistance of the plasma display device of the present invention.

FIG. 4 is a diagram showing a conventional example of a plasma display device.

[FIG. 5] FIG. 5 is a diagram showing a streaking problem of a conventional plasma display device.

FIG. 6 is a diagram showing the voltage effect of the sustain voltage corresponding to streaking and the generation of the peak value of the sustain current.

FIG. 7 is a diagram showing the occurrence of a voltage drop due to the internal resistance of a conventional plasma display device.

[FIG. 8] FIG. 8 is a diagram showing a problem of a voltage drop due to an internal resistance of a conventional plasma display device.

Explanation of symbols

[0011] 1 signal processing circuit

2 Drive control circuit 3 X electrode drive circuit

4 Y electrode drive circuit

5 Address electrode drive circuit

6 Scan circuit

7 Plasma display panel

8 Current limiting means

9 Scan drive module (SDM)

10 X electrode relay board (X—BB)

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Example 1

FIG. 1 is a diagram showing a first embodiment when the present invention is applied to an AC type plasma display apparatus. 1 is different from the conventional example of FIG. 4 in that individual current limiting means 8 X and 8 y are provided for each electrode. The current limiting means 8x and 8y are configured using resistors and the like.

In the circuit shown in FIG. 1, the current limiting means 8y is connected to the Y electrode, and the current limiting means 8y for the Y electrode is connected to the scan drive module SDM9 (Scan Drive Mojule) on which the scan circuit 6 is mounted. Is forming. In addition, the current limiting means configured using a resistor or the like is also formed on a relay board X-BB (X-Broadcast Board) 10 connected to the X electrode as 8x. Here, the current limiting means 8x and 8y have the same value, for example, the same resistance value.

By using the current limiting means 8x and 8y, the peak value of the sustain current flowing during the sustain period can be reduced, and the voltage drop of the sustain voltage can be reduced.

FIG. 2 shows the result. As shown in Fig. 2, the peak value of the sustain current waveform was reduced and the voltage drop of the sustain voltage was reduced. As a result, the voltage drop Δ Vsl at the display location S 1 shown in Fig. 5 It was confirmed that the difference from the voltage drop ΔVs2 at the display location S2 was also reduced, and the streaking value was reduced.

As a result of the experiment, when using a large plasma display panel of class 55, By setting the resistance value of the current limiting means 8x, 8y to 10 to 20 Ω, the streaking value was about 8%, which was about 4%, and an improvement effect of about 4% was confirmed.

Since the resistance per one electrode of the X electrode and the Υ electrode in the plasma display panel 7 is about 50 Ω, the resistance values used as the current limiting means 8x and 8y are the X electrode and the Y electrode. This corresponds to 20% to 40% of the resistance value per piece.

The current limiting means 8x and 8y can be replaced as long as they are means for limiting the current of a semiconductor element in addition to a resistor. For example, a diode or the like may be used. In addition, this current limiting diode may be formed in the plasma display panel 7!

[0015] Further, by using the current limiting means 8x and 8y, the voltage drop at the center of the screen caused by the sustain current can be reduced. As shown in FIG. 3, in the present invention, the voltage drop of the Y electrode voltage Vsy is reduced, and the voltage drop of the X electrode voltage Vsx is also reduced in the reverse direction. Discharge voltage (Vsy -Vsx) Force S is reduced, and the relative decrease in discharge voltage (VCy-VCx) between the X and Y electrodes at the center of the screen can be reduced. The difference in brightness between the screen and both ends of the screen can be reduced.

In the present embodiment, the case where the resistors having the same value are used as the current limiting means 8x and 8y has been described. However, the present invention is not limited to this, and the streaking can be suppressed even when the resistors having different values are used. It is clear that an effect can be obtained.

Example 2

[0016] On the other hand, considering the balance of X electrode drive circuit 3 and Y electrode drive circuit 4! /, The current path arrangement relationship to the X electrode and Y electrode of plasma display panel 7, for each electrode, When the current limiting means 8x and 8y are provided individually, the current path at the top and bottom of the screen is longer than the current path at the center of the screen, so the sustain voltage drop at the top and bottom of the screen is large. There may be a difference in brightness between the top and bottom and the center of the screen.

In this case, the current limiting values of the current limiting means 8x and 8y are set to different values for each electrode, for example, the current limiting values of the current limiting means 8x and 8y are made smaller as they go up and down. By setting so that the voltage drop due to the difference in the length of the current path can be corrected.

Therefore, in the plasma display device of the present invention, the luminance difference between the screen center and both ends of the screen can be reduced, and at the same time, the luminance difference between the screen upper and lower parts and the screen center can be reduced.

Other examples

[0017] Hereinafter, configuration examples of the present invention will be described in the supplementary notes.

Appendix 1

[0018] A plasma display panel, an X electrode drive circuit that drives a plurality of X electrodes of the plasma display panel, a Y electrode drive circuit that drives a plurality of Y electrodes of the plasma display panel, and a plurality of addresses of the plasma display panel In an AC type plasma display device equipped with an address electrode drive circuit 5 for driving an electrode,

Current limiting means for each electrode is provided between each X electrode and X electrode driving circuit, or current limiting means for each electrode is provided between Z or each Y electrode and Y electrode driving circuit. The plasma display device characterized in that the impedance of the current limiting means is 20% to 40% of the resistance value per electrode.

Appendix 2

[0019] In Appendix 1, it is divided into an odd-numbered X electrode drive circuit that drives odd-numbered X electrodes and an even-numbered X-electrode drive circuit that drives even-numbered X electrodes, and drives odd-numbered Y electrodes. AC-type plasma display device divided into an odd-numbered Y electrode drive circuit and an even-numbered Y-electrode drive circuit that drives even-numbered Y electrodes.

Appendix 3

[0020] In appendices 1 and 2, the current limiting means is configured using a resistor. A plasma display device.

Appendix 4

[0021] In the appendix 1 and 2, the current limiting means is configured by using a semiconductor element. Appendix 5

[0022] In Appendix 4, the plasma display device is characterized in that the current limiting means is configured using a diode.

Appendix 6

[0023] In Appendix 5, the plasma display device is characterized in that the current limiting means is configured by using diodes formed on the X electrode and the Y electrode of the plasma display panel.

[0024] In the plasma display device according to appendices 1 to 3, the current limiting means is formed in a scan driver module connected between the plasma display panel and the Y electrode drive circuit. Plasma display device.

Appendix 8

[0025] In the appendix 7, the plasma display device is characterized in that the current limiting means is formed in a semiconductor integrated circuit constituting the scan circuit 6 mounted in the scan driver module.

Appendix 9

[0026] In the plasma display device according to appendices 1 to 3, the current limiting means is formed on a relay substrate connected between the plasma display panel and the X electrode drive circuit. apparatus.

Appendix 10

[0027] In the plasma display device according to appendices 1 to 3, the current limiting means is on a flexible substrate connected between the plasma display panel and the X electrode driving circuit, or the plasma display panel and the Y electrode driving circuit. A plasma display device is formed on a flexible substrate connected between the two.

Appendix 11

[0028] Supplementary notes 1 to: In LO, the current limiting means increases the current limiting value at the center of the screen and decreases the current limiting value at the top and bottom of the screen. Ray equipment.

Appendix 12

[0029] The plasma display device as set forth in appendix 3, wherein the resistance used as the current limiting means has a large resistance value at the center of the screen and a small resistance value at the top and bottom of the screen.

Appendix 13

[0030] The plasma display device as set forth in appendix 11, wherein the current limiting means gradually decreases the current limiting value from the center of the screen toward the upper and lower portions. Appendix 14

[0031] The plasma display device according to appendices 4 and 5, wherein the diode used as the current limiting means has a large forward voltage drop at the center of the screen and a small forward voltage drop at the top and bottom of the screen.

Appendix 15

[0032] The plasma display device according to appendix 14, wherein the diode used as the current limiting means has a forward voltage drop that gradually decreases from the center to the bottom of the screen.

Appendix 16

[0033] In Supplementary Note 9, in the current limiting means, the voltage drop force due to the wiring on the relay substrate connected between the plasma display panel and the X electrode drive circuit is substantially equal at the end of the plasma display panel. A plasma display device characterized by setting a current limit value.

Addendum 17

[0034] The plasma display device as set forth in appendix 10, wherein the current limiting value in the current limiting means is set so that the voltage drop force due to the wiring of the flexible substrate is substantially equal at the end of the plasma display panel.

Addendum 18

[0035] In Appendix 2, the plasma display panel has ALIS (Alternate Lighting of A plasma display device characterized by using a panel with a Suefaces Method) structure.

Addendum 19

[0036] In Appendix 2, e-ALIS (extended Alternate

A plasma display device characterized by the use of a panel with the Lighting of Suefaces Method) structure.

Addendum 20

[0037] In plasma 19, the plasma display device is characterized in that the screen size of the plasma display panel is an abnormal 55 type.

Claims

The scope of the claims

[1] a plasma display panel, a first electrode driving circuit for driving a plurality of first electrodes of the plasma display panel, a second electrode driving circuit for driving a plurality of second electrodes of the plasma display panel, and the plasma display panel In an AC drive type plasma display device having an address electrode drive circuit for driving a plurality of address electrodes, an individual current limiting means is provided for each first electrode between each first electrode and the first electrode drive circuit. A plasma display device characterized in that individual current limiting means is provided for each second electrode between Z or each second electrode and the second electrode drive circuit.

[2] The plasma display device according to claim 1, wherein

The plasma display device according to claim 1, wherein the impedance value of the current limiting means is 20% to 40% of the resistance value per electrode.

[3] The plasma display device according to claim 1, wherein the first electrode is an X electrode composed of an odd number of X electrodes and an even number of X electrodes, and the second electrode is composed of an odd number of electrodes and an even number of electrodes.

The first electrode drive circuit is divided into an odd-numbered X-electrode drive circuit that drives odd-numbered X-electrodes and an even-numbered X-electrode drive circuit that drives even-numbered X-electrodes,

The second electrode driving circuit is divided into an odd-numbered Y-electrode driving circuit for driving odd-numbered Y-electrodes and an even-numbered Y-electrode driving circuit for driving even-numbered Y-electrodes.

[4] The plasma display device according to any one of [1] to [3], wherein the current limiting means is configured using a resistor.

5. The plasma display device according to claim 1, wherein the current limiting means is configured using a semiconductor element.

6. The plasma display device according to claim 5, wherein the current limiting means is configured using a diode.

7. The plasma display device according to claim 6, wherein the current limiting means is configured using a diode formed on the X electrode and the Y electrode of the plasma display panel.

8. The plasma display device according to claim 1, wherein the current limiting means is a plug. A plasma display device formed in a scan driver module connected between a plasma display panel and a Y electrode drive circuit.

[9] The plasma display device according to claim 8, wherein the current limiting means is formed in a semiconductor integrated circuit constituting a scan circuit mounted in a scan driver module. Display device.

10. The plasma display device according to claim 1, wherein the current limiting means is formed on a relay substrate connected between the plasma display panel and the X electrode driving circuit. Display device.

11. The plasma display device according to claim 1, wherein the current limiting means is on a flexible substrate connected between the plasma display panel and the X electrode driving circuit, or the plasma display panel and the negative electrode drive. A plasma display device formed on a flexible substrate connected to a circuit.